Mark Harmon's Gibbs is such an iconic NCIS character, and his list of rules cemented him as one of the best. Although Harmon's Gibbs left NCIS in season 19, he remains a vital character to the show.

When NCIS premiered in September 2003 with "Yankee White," which still stands as one of the best episodes over the series' long-run, one of the first things we learned about Mark Harmon's Leroy Jethro ...

Throughout his run in the "NCIS" franchise, Special Agent Leroy Jethro Gibbs (Mark Harmon) has followed a code — a set of rules, if you will. These self-imposed edicts inform both his personal and ...

For years, fans of NCIS knew exactly who Leroy Jethro Gibbs was: a man of few words, a hardened leader with a strict moral code, and the creator of a legendary set of rules. But now, with NCIS: ...